RSS Aggregator by Feedzy – Feed to Post, Autoblogging, News & YouTube Video Feeds Aggregator <= 4.3.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Error Message

The RSS Aggregator by Feedzy – Feed to Post, Autoblogging, News & YouTube Video Feeds Aggregator plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in all versions up to, and including, 4.3.3 due to insufficient input sanitization and output escaping on the Content-Type field of error messages when retrieving an invalid RSS feed. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.